TOKYO : A powerful earthquake registering 6.8 on the Richter scale shook Japan on Tuesday, reportedly injuring a number of people and swaying buildings in the heart of Tokyo.
Bullet trains, a nuclear power plant and elevators were automatically shut down as a precaution after the quake hit at 11:46 am (0246 GMT) off the Pacific coastline of Miyagi prefecture, 300 kilometres (185 miles) north of Tokyo.
The meteorological agency issued a tsunami alert, predicting seismic waves of 50 centimetres (20 inches).
Officials said they were still gathering information on casualties, but Kyodo News said many people were reported to be injured.
The quake was the same magnitude as one in October last year in central Niigata prefecture that killed 40 people. That was the strongest earthquake in quake-prone Japan in a decade.
"I was on the second floor and felt as if I was suddenly tossed up. Then there was a long, sickening spell of horizontal shakes," said Wakako Suzuki, 31, who lives in Miyagi prefecture.
"My first-aid kit fell from the closet and neighbours rushed out of their houses. Mother went to the cemetery to check if our family gravestone was all right," Suzuki told AFP by telephone.
The quake was felt strongly in the heart of Tokyo, automatically shutting down elevators and swaying high-rise buildings.
Misao Hoshi, an elderly woman in southern Miyagi, said she was eating lunch when the earth began shaking but the quake had caused no major damage at her home.
"After we heard there was a tsunami alert, we went outside to see our well. If there is really going to be a tsunami, the surface level usually goes up. But it was the same as usual.
"A few dishes fell from our kitchen shelves. But that was it. We are again eating lunch," she said.
Japan is home to 20 percent of the world's major earthquakes and is always bracing for the dreaded "Big One" predicted to hit in the future.
Last month thousands of volunteers and rescue workers took part in one of Japan's largest-ever tsunami drills, anxious to prevent a repeat of the devastation seen in December's Indian Ocean catastrophe.
- AFP /ct